Method and means for improving the utilization of volatile refrigerants in heat exchangers



Nov. 22. 1955 c. E. LOWE 2,724,246

METIZOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTSIN HEAT EXCHANGERS Filed April 1, 1954 6 Sheets-Sheet l LB 5 (r3 (1) &INVENTOR. CHERJJES 12. ow

PXTTORNYCY NOV. 22, 1955 c, E, LOWE 2,724,246

METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTSIN HEAT EXCHANGERS Flled April. 1, 1954 6 Sheets-Sheet 2 mnmw ME I m 2mM M NW C RT TO RN TzY NOV. 22, C. E. LOWE METHOD AND MEANS FOR IMPROVINGTHE UTILIZATION OF VOLA'IILE REFRIGERANTS IN HEAT EXCHANGERS Filed April1, 1954 6 Sheets-Sheet I5 FIGES.

Li INVENTOR. ,1 cHf-iRLEs 32.);ow

fTTORNEY NOV. 22, 1955 c E LOWE 2,724,246

METHOD AND MEANS FOR TMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTSIN HEAT EXCHANGERS Filed April 1, 1954 6 Sheets-Sheet 4 IN V EN TOR.CiHBRLES 2. LOWE,

FIGA.

BTTORNEY Nov. 22, 1955 c. E. LOWE 2,724,246

METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILE REFRIGERANTSIN HEAT EXCHANGERS Flled ApIlL l, 1954 6 Sheets-Sheet 5 INVENTOR. RLfiE- L E ETTORNEY Nov. 22, 1955 C. E. LOWE METHOD AND MEANS FOR IMPROVINGTHE UTILIZATION OF VOLATILE REFRIGERANTS IN HEAT EXCHANGERS FiledApril 1. 1954 FIG. 10.

6 Sheets-Sheet 6 INVENTOR. HARLES E.LOWEJ :BTTORNEY i United StatesPatent O METHOD AND MEANS FOR IMPROVING THE UTILIZATION OF VOLATILEREFRIGERANTS IN HEAT EXCHANGERS Charles E. Lowe, Orlando, Fla.

Application April 1, 1954, Serial No. 420,395 11 Claims. (Cl. 62115) Thepresent invention relates to heat exchange systems employing a volatilerefrigerant liquid and which may be used for the heating or cooling ofwater, air, or of other gases or liquids, ,as in heat-pumps,refrigeration, air-conditioning or ice-making apparatus or the like, andis concerned more particularly with the more efficacious employment ofthe refrigerant in an evaporator or workperforming ,heat exchangeinstrumentality. This application is a continuation-in-part of myco-pending application, Serial No. 314,364, filed October 11, 1952.

Heretofore, and so far as is known, insystems employing heat exchangersof the evaporator type-into which a volatile refrigerant is dischargedfor contact with tubes, coils or other surfaces to effect aheat-exchange therebetween and thus vaporize the refrigerant into alow-pressure fluidthe normal charge of refrigerant is such as tosubstantially flood the evaporator or to have a substantially largequantity of the liquid refrigerant retained in the bottom portion of theevaporator during the operational cycle. This has resulted in very slowand sluggish vaporization of the refrigerant with an accompaniedinefliciency in the output of the heat exchanger unit.

Attempts have been made to overcome this situation by introducing theliquid refrigerant at the sides or at the top of the evaporator or bythe employment of baflies to guide and direct the refrigerantall for thepurpose of causing the liquid refrigerant to flow over the surfaces ofthe evaporator to better absorb the heat therefrom and to vaporize.Another such attempt has been to introduce a portion of thehigh-pressure liquid refrigerant through jets and/ or injectors into anevaporator flooded with low pressure or expanded liquid refrigerant forthe purpose of creating a circulating movement of the liquid refrigerantwithin the evaporator, as in United States patents to Phillips No;2,123,021 or to Boileau No. 2,132,932. These attempts toimprovevaporization of the liquid refrigerant in, so-called, floodedsystems could have theoretically some beneficial results in givencircumstances, but, so far as I know, they are not employed, Further, ithas been proposed to by-pass a portion ofthe high-pressure gaseousrefrigerant from the compressor of the system to act as the impellentfor aspirating low-pressure or expanded liquid refrigerant in anevaporator, as in United States Patent No. 2,159,251, thus short cyclingpart of the capacity of the compressor or other refrigerant pump.

Furthermore, prior to my invention, heating and cooling systems of thereversible type, wherein there is a heatexchanger that serves as acondenser on the cooling cycle and as an evaporator on the heatingcycle, the charge of refrigerant in the system is controlled by thatrequired for the cooling cycle and which, usually is more than requiredfor the heating cycle. Nevertheless, during the heating cycle in such asystem, the greater portion of liquid refrigerant, discharged into theevaporator (usually through an expansionvalve), does not quicklyvaporize but flows into and remains on the bottom of the evaporator andis not sufiicient in volume to properly flood or contact the heatingsurfaces of the evaporator so as to be 2,724,246 Patented Nov. 22, 1955vaporized to best advantage, thus resulting in slow and inefficientvaporization. To increase the amount of the refrigerant charge abovethat required or permissible for the cooling cycle in such systems of agiven size or rating, to partially overcome the condition justmentioned, would raise the head pressure in the system to a point thatwould be dangerous and damage the system or would cause the safetydevices to shut-off and open with such frequency that the efiiciency ofboth the cooling and heating cycles would be of little or no utility. t

Also, in some systems, where water tubes or coils are disposed withinthe evaporators, the water flowing in said tubes or coils freezescausing inefficient operation or a shut-down of the system until thecondition is remedied or, should the tubes break or rupture, allowingthe water to flow into the conduits for the refrigerant and hencedamaging the system. i

I have found that superior results are obtained, in any given case, atmuch less cost and with a smaller evaporator by introducing onlyhigh-pressure liquid refrigerant into a non-flooded evaporator, by meansof an atomizing injector or aspirator pump, which also functions as arestricter to nebulize the high-pressure liquid refrigerant,

compressor (or its equivalent) as a low pressure gas;

and any of the nebulized refrigerant that is not vaporized may berenebulized with the injected on-coming charge of high-pressure liquidrefrigerant. In practice I have found that the amount of unvaporizedrefrigerant is relatively small during the cycle of operation and that Ineed to use only about 30% of the normal charge of liquid refrigerantemployed in a flooded type evaporator or chiller and approximately 50%employed in the, socalled, dry expansion chillers (now most generally inuse) with a much smaller evaporator for a given work-load, resulting ina more rapid response from the system and a greater work output atlesscost then heretofore.

The object of the present invention, therefore, is to render evaporatorunits, when used as a chiller or inheat exchange systems of a heat-pumpor the like, more efficient than heretofore obtainable by substantiallyincreasing the output of a given system and, in some systems, the sameresult is obtainable with a liquidrefrigerant charge substantially lessthan that previously regarded a normal charge for such system. t

Another object of the invention is to provide an improved injectornozzle which has an accelerated pick-up of the liquid being injected orpumped thereby. A still further object of the invention is the provisionof an improved type of heat exchanger which may be used either as acondenser or vaporizer, which is not susceptible of being ruptured, byfreezing, with all of the attendant disadvantages known in the art as aresult there of and which is relatively inexpensive to manufacture.

The objects of the present invention may be attained in a veryinexpensive and practical manner by providing one or more injector(aspirator-pump) nozzles in the bottom of a non-flooded chamberedevaporator and through which the liquefied refrigerant is introducedinto the evaporator at substantially condenser pressure, the type ofnozzle being such as to function as a restrict'or to expand and nebulizethe liquid emittedtherefrom and as an aspirator-pump. The bottom of theevaporator may be (and preferably is) provided with one or more sumpsinto each of which an injector nozzle is operatively disposed. Thenozzle is so placedor, when more than one is employed, are spaced alongthe said bottom--to cause the nebulized refrigerant to fill the entirevaporizer and absorb the heat .from the surfaces thereof, thusvaporizing the refrigerant very rapidly which vapor passes from theevaporator. Such small portion of nebulized liquid refrigerant, that hasnot been vaporized, drops to the bottom of the evaporator and flows tothe sump where it is picked-up by such injector nozzle or nozzles andagain entrained and nebulized thereby with the on-coming highpressureliquid refrigerant in a continuing cycle with the result that verylittle liquid refrigerant remains on the bottom of the vaporizer at anyone time, i. e., often less than two inches in depth. It is preferredfor efficient operation that the discharge end of the nozzle project, atleast, slightly above the normal liquid refrigerant lever in g theevaporator.

. While this nebulization of the liquid refrigerant may be accomplishedwith any suitable chambered evaporator, it is preferred to employ anovel type of vaporizer consisting of a vertically disposed casinghaving greater height andwidth than depth, over the exterior surfaces ofwhich flows a heat-bearing ora cooling liquid (as the case may require);and that the interior and exterior surfaces of the evaporator beprovided preferably with vertically disposedfins to more quickly effectthe heat exchange, the bottom wall of casing having one or more of myimproved injector nozzles disposed in and supported there- .bytodirectthe emitted liquid refrigerant introduced into the casing upwardlythereof, and there being a vapor take-off in the casing above saidnozzles.

Other objects and advantages of the present invention will'be apparentas the detailed description of this invention proceeds.- v

In the drawings, which illustrate several adaptations of the inventionsas -now-devised and used,

Figure .1 is :a schematic illustration of a system for heating wateremploying my invention;

Figure 2 is a schematic illustration of a system for cooling wateremploying my invention;

Figure .3 is a .schematic'illustration of a conventional reversiblecycle :heating and cooling system which has beenmodified to incorporatethe present invention at X;

Figure 4 is a schematic illustration of a reversible system for makingice or chilling water employing my invention;

Figure 5 is a longitudinal sectional view through the improved injectornozzle of my invention which is em- ,ployed to carry out the objects ofthe invention and illustrated as being disposed in a sump-portion of aheat exchanger; 7

Figure 6 is a section of the improved evaporator equipped with theimproved injector nozzle and taken substantially on line 6-6 of Figure4;

Figure 7 is a fragmentary transverse sectional view of the improvedevaporator and'taken substantially on line 77 of Figure 6;

characters of reference refer to similar and like parts; and, as can beobserved, the drawings show the improvementsof this invention in severaladaptations to illus- :trate the principles'thereof.

Figures 1 and v2 illustrate very simple systems employ- .ing 7 theimprovements of this invention :and each :system comprises a condenserand an evaporator, as at 11 and 12 ply, such as water for one example.

and at 11 and 12 respectively, interconnected by suitable tubing or pipewith a compressor, or its equivalent, as at 13 and 13 respectively in aconventional manner but without the interposition of the conventionalexpansion valve between the condenser and the evaporator, the systemshown in Figure 1 being arranged to function as a heat-pump and thesystem shown in Figure 2 being arranged to function as a cooling orfreezing unit.

While the condensers and evaporators are shown in Figures 1 and 2 asbeing in accordance with the improvements of this invention, it isobvious that they be of any other operable type, provided, that withrespect to carrying-out the nebulization of the volatile refrigerantliquid, the evaporator should be of hollow chamber type havingheat-bearing surfaces associated therewith and into which evaporator thehigh pressure liquefied refrigerant is discharged, through an injectornozzle X, to produce an agitated mist or spray that fills the evaporatorand continuously bathes the heat-bearing surfaces of said evaporator.Since the evaporator chamber willbe under muchless pressure than theentering refrigerant, the nebulized refrigerant, :due to its expansion,is distributed throughout the evaporator chamber in a continuousmovement over its interior surfaces and will more quickly andefliciently collect the heat from the said heat-bearing surfaces of the.evaporator, thus vaporizing or gasifying rapidly, and will be drawn ,asa low-pressure gas to the suction sideof the compressor or itsequivalent. Should any of the nebulized refrigerant accumulate withinthe evaporator in liquid form, -it is entrained by the injector nozzle,X with the oil-coming charge passing therethrough and be renebulizedthereby, thus maintaining substantially all the liquid refrigerantwithin the evapo rator, during the cycle of operation, in a finelydivided and agitated state.

With particular reference to the heat-pump shown in Fig. '1, thecompressor 13, when operated, circulates the refrigerant in the systemin .the direction of the arrows, drawing into it the low pressuregaseous refrigerant within the .evaporator'12 through a return,COl'ldlllt 14 and discharging it, .asa hot high pressure gas, intoanoutlet conduit .15 throughwhich it flows to the condenser 11 wheresaid gaseous refrigerant is liquefied. This high pressure liquefiedrefrigerant then ,passes from: the condenser 11 through a conduit 16 tothe evaporator l zinto which the liquid refrigerant is nebulized,through as aspiratoror injector :nozzle X-under the condenser pressure,to fill 'the evaporator with a mist or fine spray that impinges ,uponandbathes all the surfacesof theevaporator. This-nebulizationof theliquid refrigerant causes quick and speedy vaporization of therefrigerant, which vapor or gas is drawn by the compressor 13 thereintothrough conduit 14 and is again compressed in a continuous cycle. Theheat-pumpof Fig. l derives its heat from -t-he; con denser 11, which maybe of the radiation or air cooled-type 20 and ll 'shown in Figures 3. and.,4, respectively,-but is-here shown ,asa water cooled type ,whereinthecooling water is sprayed or :flows from a distributor head 17 and, bypassing over the condenser .11, ,quicklys-absorbs the heat from the hotgases therein, the hot ;water being'collected in a tank or receiver .18from which it ;is -,circulated, as .by a .purnp 19, through aheating-system, containing a radiator or radiators .or otherutilitar-ian unit, generally indicated-at .20, which-dissipates the heatfromthe water, The unit .20 may be connected with .thedistributonheajd17 to deliver cooled-waterto vthe condenser. A replenishing or make-upwaterline may :be ;connec ted,.as at 2/1, to the tank 18. A distributorhead 22,;similar to-the1head 17, is ;arra-nged over the evaporator :12and connected to .a suitable source .of a :heat-bearing transfer agent aof sup- A collector tank 23 underlies the evaporator 12 to receive the-transfer agent that-has flowed over the evaporator. Thetankzs may beconnected to a waste-pipe or the transfer agent therein may berecirculated to the head 22 after its temperature has been permitted torise for its functional put poses, as by being circulated in pipessubjected to anambient air or buried in the earth for two examples.

Figure 2 discloses a system similar to that shown in Fig. 1 with thesame parts rearranged to function as cooling apparatus, said parts beingdesignated by the same reference numerals as in Fig. l but raised by theexponent a. i It will be observed that the circulating system for theheat transfer agent, which includes the parts 17*, 18 19 and 20 isarranged in association with the evaporator 12 instead of beingassociated with the condenser 11 as in Figure 1; and the distributinghead 22* and the collector tank 23 are arranged in association with thecondenser 11 instead of being associated with the evaporator 12, as inFigure l. With this arrangement, it is clear that a heat transfer agentor medium, discharged from the distributing head 17 and flowing over theevaporator 12 is cooled and delivered to the radiator or other coolingunit or device ZO -and is returned to the type shown in Figure 3 as areversible cycle system. Such conventional reversible-cycle heating andcooling system generally comprises a compressor 13 having its intake anddischarge sides connected with a conventional reverse-cycle valve 24controlled by a suitable actuator, indicated at 25, and which actuatormay, in turn, be thermostatically and/or manually controlled in any wellknown manner now commonly practiced. The reverse-cycle valve 24 isconnected by a conduit 14 to a heat exchanger M -12 which alternatelyserves as a condenser and evaporator, and is here shown. as theconventional cylindrical type heat exchanger having internal water tubes26 connected with and controlled by a conventional supply meansindicated at 26*. The reverse-cycle valve 24 is also connected by aconduit 15" with a radiator 20 through which ambient air may be forcedby a fan 27. In accordance with the present improvement, the bottom Wallb of the heat exchanger is provided with one or more injector nozzles X,as previously explained, and connected with the radiator 20* by conduit16 This conduit connection 16* may have included therein, adjacent theradiator 20*, a conventional expansion valve 28 which discharges into adistributing head 29 from which the expanded refrigerant passes throughtubes 29 to the radiator 20". Of course, it is understood that othertypes of heat exchangers may be employed instead of the radiator 20 butwhere an expansion valve 28 is employed the conduit 16 is provided witha bypass tube p to by-pass the expansion valve 28. The by-pass tube p isprovided with a check valve v positioned to close against the flow oftherefrigerant from the exchangerl1 ll2 to the expansion valve 28 and toopen when the flow of the refrigerant is from the radiator 20* throughthe conduit 16 to the heat-exchanger 11 --12 The arrangement shown inFigure 3, when functioning as a heat pump system, is such thatthereverse-cycle valve 24 will be actuated to allow the refrigerant topass from the discharge side d of the compressor 13*, as a hot highpressure gas, into the pipe 15 and fiow directly to the radiator 20 itbeing noted that the expansion valve 23 is now closed or inactive due tothe provision of the usual equalizer tube 28* and the feeler-bulb 28connected, respectively, with the radiator 20 and the conduit 15 (whichis now the hot high pressure gas line). Cooler ambient air, or returnedair from the system, is drawn or forced by the fan through the radiator20 and isheated by extracting the heat from the gases in said radiator,which now acts as a condenser and liquefies the refrigerant therein as ahigh-pressure liquid. The refrigerant flows, as a high. pressurecondensed liquid, from the radiator 20 through the tubes 29*,distributing head 29, by-pass p and conduit 16 to the in 6 spirator orinjector nozzle or nozzles X in the bottom b of the heat exchanger 11-12 and is nebulized therein in the manner indicated by the arrows andas previously explained, forming a low pressure gas which is drawn bythe suction side of the compressor 13 through the tube 14 back into thecompressor in a continuous flow. The injector nozzles X, in Figure 3,may be inserted directly into the bottom b of the heat exchanger 11-.--12 or the heat exchanger may be provided on its bottom with aplurality of sumps as shown in Figure 5.

When the valve 24 is actuated to reverse the cycle of the system tofunction for cooling, the hot compressed refrigerant gas, dischargedfrom the compressor 13 at d, is delivered through the conduit 14 to theheat exchanger 11"----12 and passes over, or otherwise contacts, thetubes 26, thus liquifying the hot gas.

The liquified refrigerant drops to the bottom of the heat exchanger 1l-12 and passes, as a high pressure liquid, through the nozzles X in thebottom thereof and through the conduit 16 to the expansion valve 28where the liquid refrigerant is discharged into a distributing head ordrum 29 and, thence, through the tubes 2% into individual portions of acoil or radiator 20". Air passing through the radiator, by means of thefan 27, is chilled; and the refrigerant, absorbing the heat from theair, is converted into a low pressure gas and returns to the suctionside s of the compressor 13 through the conduit 15 From the disclosurethus far it will be manifest that the nebulization of the liquidrefrigerant may be accomplished in any suitable type of chambered heatexchanger by means of one or more injector nozzles X, shown in Figure 5,threaded in the bottom side of the heat exchanger, or said nozzle may bewelded or soldered in position. It will be manifest also that, shouldthe nozzles X in any given case be found too restrictive of the flow ofthe condensed refrigerant when passing from the heatexchanger, such as11 --12 to the heat-exchanger 20 in Figure 3, when the system isfunctioning for cooling purposes, a bypass, provided with a one-waycheck valve, similar to by-pass 2, may be employed between the interiorof the heat-exchanger li -12 and conduit 16 to permit the free flow ofthe high-pressure condensed refrigerant to the conduit 16 but which willclose to the passage of high-pressure liquefied refrigerant from theconduit 16 to the heat-exchanger lir -12 and, thus direct such passageof the high-pressure condensed refrigerant entirely through the nozzlesX at condenser pressure.

As many of such nozzles X may be employed in spaced relation along thebottom of the evaporator as may be found sufiicient to fill the samewith the nebulized refrigerant, according to its size or capacity, andwhich, during the injecting operation, will maintain the unvaporizedliquid refrigerantthat may drop to and accumulate on the bottom of theevaporator-to a point just above the injector passages 36 of the nozzleX and below its discharge orifice 35 (see Fig. 5), or to cover saidorifice in some other types of injector nozzles which may be employedand which have to be primed to start the injecting operation. Theexterior ends of the nozzle or nozzles X is or are connected to a supplyconduit, such as 16, 16 or 16'. It is preferred that the nozzles X bedisposed in sumps 38 formed in a bottom wall b of the evaporator, asshown particularly in Figure 5. Each sump is dimensioned so that theaccumulated liquid will drain and collect therein and that the top ofthe sump is, at least, above the injector passages 36 of the injectornozzle and it is preferred that the discharge orifice 35 of the injectornozzles X project above their sumps 38 and above the normal liquidlevelin the evaporator.

The injector nozzle X, shown in Figure 5, is of my improved constructionwhich gives extremely quick acceleration and force in injecting orentraining the liquid refrigerant in the bottom of the heat-exchanger.

30. projecting from one end of a threaded boss 31 havinga. wrench-head32 on its other end. The jet nozzle 30 is conical externally andinternally terminating in an axiallydisposed discharge opening 30 andcommumcating at its base with a passage 33 in said boss and-wrenchhead.32. The passage 33 is internally threaded to receive the threaded end ofthe conduit tube, suchas 16, 16 or 16' Surrounding the impeller jetnozzle 30 is a sleeve 34 which has its inner end suitably secured to theboss 31 in any suitable manner, soldering being shown. The interior ofthe sleeve 34 is formed to provide a Venturi throat 35 at a distancebeyond the discharge opening. 30 of the impeller jet, this throat beingpreferably formed by having its inner portion 35 conical and spaced fromthe exterior conical surface of the impeller jet 30 and converging tothe throat 35 and by having its outer portion 35 formed with a conicalsurface diverging from said throat 35 to provide the discharge orifice35 The crosssectional area of the throat 35' should be in the order ofabout twice that of the crosssectional area ofthe impeller jet opening30 Injector passages 36 are provided in the sleeve 34 to communicate theexterior of the sleeve with the interior thereof and are positioned at apoint in the sleeve between its inner end and the impeller-jet opening30*, these passages being preferably circumferentially about the sleeve.The injector passages 36 may be of any configuration or dimension, butit is preferred that they compose a circumferential series of passagesof about ,4 inchin diameter to form strainer screen to exclude sedimentor any foreign matter larger than the throat 35 from passing into theinjector nozzle, the total opening area of the passages 36 being inexcess of the space area bet-ween the inner surface of the sleeve 34 andthe jet nozzle 30 at the point where they oppose, and, preferably, notless than 3:1 with respect to the narrowest cross-sectional area of thethroat 35, thus providing adequate admission of the liquid to beinjected or pumped. The nozzles X may be periodically cleaned by merelyunscrewing them; however, in practice it has been found thatthis screenis an over-precaution and seldom needs to be cleaned.

The injecting action of the injector nozzle X is m'aterially enhanced bythe provision of an interceptor bar or bafile 37 extending transverselyacross the passage of the impeller-jet 30 at a point substantiallyinwardly of and aligned athwart its orifice 30 as shown in Figure '5' ofthe drawings. This transverse baflle 37 consists of-a bar or rod havingits ends swedged or soldered in suitable openings drilled in the nozzlewall. The surface of the bar opposing the flow of the impeller liquidthrough the jet 30 is flat, as shown at 37 in Fig. 5, and is of a widthto obstruct about one-third of the area of the passage in the jet nozzle30 at the point where the bar is posi-- tioned. The back surface of thebar 37 may be rounded, as shown.

that by the employment of the bar 37 with the flat surface 37*, theinjecting action of the nozzle X has been greatly increased by thepropelling action of the impelling refrigerant emitted from the impellerjet30 and creates such a suction orimpelling-actionon the fluid, beinginjected through the injector-passages 36, that the injection action canbe started without priming or the liquid covering the top of theinjector-nozzle so long as the liquid merely covers the injectorpassages 36. In the use of my injector nozzle X constructed as above,with the jet discharge opening 30 of inch in diameter and and l0; areconstructed; in accordance with my present improvement; to etfecvquickheat 'exchange'in connec- From practical operation, it has-been foundtion 'with'a nebulized volatile refrigerant and to preventdamagethereto, due to freezing of the heat-transfer agent or medium and/or itsseepage into the system with the refrigerant clue to rupture caused bysaid freezing. This improved heat-exchanger may serve eitherv as anevapo-' rator or-as a condenser, as shown; but, when used as acondenser, it need not'be equipped with the nozzle X except in areversible system where the heat-exchanger acts alternately as condenseror an evaporator accord ing to the direction of cycle of operation, asis well understood in the art.

The detailed construction. of the heat-exchangers 11, 11*, 12 and 12 ismore. particularly shown in Figs. 6 and 7; and, in addition to its abovementioned advantages, also may be employed as an ice-maker, as will belater described. These heat-exchangers comprise a vertically' positionedand generally rectangular shaped casing C having a height and widthgreater than its thickness-or depth. The casing ispreferably-constructed from sheet metal with spaced and opposedsidewalls s, end wall e, bottom wall b and a top wall t. The dimensionsof the casing C may be that designed for a required or given capacity.When the casing .C is to be used as a heat-exchanger with a liquidheat-transfer agent or medium, such for instance as water; its sidewalls s converge upwardly, as shown, so that the heat-transfer agent mayflow downwardly and exteriorly of'the. casing. C from an overlyingsource of supply. If the side walls s converge upwardly, as shown inFigs. 1, 2, 4, 6 and 7, as preferably for use withra liquid transfermedium, the top'wall t may be omitted and the top edges of the sidewalls s may meet. When employed asan evaporator, the bottom wall b ofthe casingC is provided with one or moresurnps 38 in which a nozzle X isdisposed, as explainedabove.

The exterior, and preferably the interior, surfaces of the casing C areprovided with finsf to accelerate the heat exchange. These fins,preferably formedof elongated strips of sheet metal,substantiallyright-angular in cross-section, are arranged vertically onsaid surfaces of the side walls s and end walls e extending from the topto the bottom thereof and lying in close relation with one of theirangular portions fiat against said walls and secured thereof by weldingor soldering, thus reinforcingsaid walls.

In Figures 8 and 9 isshown a further extensionof my improved evaporatorC which may be employed in any system having a pressure differentialfrom a high to a low side and does not require internal circulatingtubes therein, but may be submerged in a heat medium from which heat maybe extracted by conductivity or radiagive rigidity to the same, ifnecessary. One or more injector nozzles X may extend into the bottom ofthe chamber C through the bottom wall 43 to direct its spray upwardlyinto the chamber C and connected (as described in connection with Figs.1, land 3) to a high pressure conduit'16, 16 or 16, whereby theliquefied refrigerant will be nebulized by theinjector nozzles X,.

as previously explained, until-it has absorbed sufficient heat from theside walls of the chamber. C to gasify and 1 discharge from the chamberC through conduit 14, as

a low pressure gas.- The charge of refrigerant required, with the heatexchanger C, may be only enough to keep thepassages 36 in the injectornozzles -X covered innormal operation, as indicated, thereby usingrlessrefrigerant and functioning more effectively. Of 'course, fins flshownin Figs. 6 and 7, may be arranged within, as well as as panels in thewalls of buildings and which does not require the use of expensivecooling coils or of a isocalled honey-comb construction. This coolingunit, like the heat-exchanger shown in Figs. 6, 7, 8 and 9, comprising arather narrow vertical disposed elongated chamber C" having side walls50, end walls 51, a top wall 52 and a bottom wall 53, all of heatconducting material, and the side walls may be connected by stayrods 54to give strength and rigidity to the structure, if

necessary. Baffles 55 are thermally connected to the walls of andsuitably arranged in said chamber C to deflect and transfer, one to theother, liquefied refrigerant emitted into the top of said chamber and todirect it downwardly to the bottom of said chamber. One or more injectornozzles X may extend into the chamber C" through the bottom wall 53 andconnected to conduit 16 supplying a high pressure liquified refrigerantthereto. Connected to each injector nozzle X is a vertical pipe 57extending to the top of the chamber C? and provided with a downwardlydirect discharge end 57, whereby the nebulized refrigerant showersdownwardly of said chamber and is intercepted by said baflies 55, thusabsorbing the heat from the walls of said chamber. Any refrigerant thatis vaporized by this action passes as low pressure gas back to thecompressor, or the like, through pipes 14 as shown in Figs. 1 and 2; butsuch of the refrigerant which is not vaporized falls into the bottom ofthe chamber C" and is again picked-up (as previously explained) byinjection through passages 36 in said injectornozzles X and redischargedat 57 until it has absorbed suflicient heat to gasify and discharge fromthe chamber C" through low pressure conduit 14. If desired, the exteriorsurfaces of the side walls 50 may be provided with fins 7 as shown inFigs. 6 and 7.

Further utilization of the improvements of my invention is shown inFigures 4 and 6, wherein there is disclosed a novel system for makingice and/or chilling water for commercial purposes.

sheet toa permissible or desired degree, anyexcess water flowing intothetank 23 for recirculation. When the desired thickness of ice hasformed on the walls of the evaporator 12, the reverse-cycle valve 24 maybe manu ally actuated, or may be automatically actuated by a controlmeans 25, shown in Fig. 3 or other equivalent means, which in turn ispreferably actuated by a timing device or thermostat not shown, to causethe hot refrigerant gas, from the compressor 13, to flow directly intothe evaporator 12 by means of pipe 14, where the heat of said gas causesthe ice adhering to the surfaces of the evaporator to drop therefrominto a bin 60. The bottom of the bin may have a conveyor belt 61 thereinto move the ice therefrom. After a predetermined time lapse, the controlmeans is again actuated, either by said timing means or by a thermostat62, to operate reversecycle valve 24 to reverse the operation of thesystem to repeat its cooling or freezing operation, just described,until the machine is shut-down or stopped. Of course, it is understoodfrom the foregoing description that, after the hot refrigerant gasenters the evaporator 12 from pipe 14 during the heating cycle, itliquifies and returns to the condenser 11 through pipe 16 where itvaporizes and passes to the suction side of the compressor 13. The finsf, on the exterior surface of the evaporator 12, will cause the ice toform much more rapidly and in long and narrow strips that are easilyhandled and may be easily broken to desired lengths or crushed.

The apparatus shown and described in connection with Fig. 4 may also beeconomically employed for chilling water for commercial or industrialpurposes and, to this This novel system is preferably of the reversiblecycle type similar to that shown in Figure 3 and may comprise acompressor or equivalent 13, a reverse-cycle valve 24, a condenser 11,an evaporator l2all conveniently arranged and interconnected in theusual manner. The condenser 11 may be of any desired or convenient type,but is here shown as an air cooled type. The evaporator 12 is of thetype, hereinbefore described in connection with Figs. 1, 2, 6 and7,comprising a, vertically disposed hollow casing having bottom wall b,upwardly converging side wall s and relatively narrower end walls e, thebottom b having one or more sumps 38 therein, in which are mountedinjector nozzles X preferably of my improved type above described. Awater distributor head 22 is arranged and supported over the apex of theside-walls s to direct a water spray downwardly onto the decliningsurfaces thereof. The distributor head 22 is supplied from a suitablesource, which may be an open tank 23 disposed under the evaporator 12 tocatch water that may flow therefrom. The tank 23 may be supplied by afeedpipe 21 controlled by a water-level means 39; and the water from thetank 23 maybe pumped therefrom to said distributor head 22, by a pump19. With this arrangement, water discharged from the distributor head 22flows over the exterior surfaces of the side walls s of the evaporator12 and is caused to freeze thereon, during the nebulization therein ofthe high pressure liquefied refrigerant flowing thereto through pipe 16from the condenser 11, which, in turn, receives. hot refrigerant gasthrough pipe 15 from the discharge side of the compressor 13. Thegradual freezing of said water flowing from the head 22 will increasethe thickness of the ice end, the cold water flowing down the side-wallss of the evaporator may be collected in the tank 23 and the distributorhead may be connected directly to the supply pipe 21, the pump 19 beingemployed to discharge the cold water to a service system, and, in suchcase, the water-level control valve 39 may not be used.

Having thus described my invention and the several manners in which thesame may be performed, it will be seen that the objects thereof areattained by the con structions therein disclosed; but, since the saidconstructions are susceptible to modifications and variations (some ofwhich being stated and others being obvious after stating my invention),it is to be understood that the invention herein described is to belimited only by the scope of the appended claims.

Letters Patent is:

1. As a method of more effectually utilizing a volatile liquifiedrefrigerant in a circulating heat-exchange system having acondenser-means and an enclosed evaporator-chamber with heat-transfersurfaces; the steps of continuously passing to said chamber only theliquified refrigerant, coming from said condenser means, while underpressure from the condenser and discharging the same into said chamber,under said pressure, in a nebulized stated causing all but a smallpercentage of said discharged refrigerant to flash and causing .anon-flooded condition of said chamber, during the operation of thesystem; said discharge of the refrigerant into said chamber inspiratingtherewith any unvaporized refrigerant that has been previouslydischarged and collects in said cham her, as a liquid body, torenebulize the same; and drawing the vaporized or gasified refrigerantfrom said chamber intothe system.

2. As a method of more effectually utilizing a volatile liquifiedrefrigerant in a circulatingheat-exchange system having a condensermeans and an enclosed evaporatorchamber with heat-transfer surfaces; thesteps of continuously injecting in a nebulized state all of thecondensed liquified refrigerant, coming from the condenser means,directly into the non-flooded evaporator chamber and under condenserpressure, during the operation of the system, causing rapid gasificationof said refrigerant; said injecting of said refrigerant in said chamberinspirating therewith only, thenebuli zed. refrigerant that collects inthe chambenas a .liquid body, to renebulize the same; anddrawingtth evaporized or gasified refrigerant from said chamber into thesystem. 7

32 In an apparatus employing a circulating refrigerant andmwhich.includes a system having a condenser means for converting-therefrigerant, in its gaseous phase, to a high pressure liquid and. aheat-exchanger to-gasify said high-pressurealiquid; the improvementbeing-that saidheat-exchanger has an enclosed chamber therein connectedin-said system, ,one orv more atomizing injector nozzles located insaidchamber and connected-directly to-the condenser insaid system tohave allof the refrigerant from the condenser pass therethrough in itsliquid phase-and substantially undercondenser pressure, during theoperation-of said-system, whereby said liquefied refrigerant acts as .ahigh-pressure liquid impellant pumping medium for said injector nozzleor nozzles, which latter ncbulizes the liquefied refrigerant passingtherethrough; thearrangement being such that-the emitted nebulizedliquid refrigerant impinges upon and contacts the interior surfaceswithin said -chamber,.efiecting quick gasificationof-the refrigerantwithout floodingsaid chamber with a liquid body, and inspirates anyungasified low-pressure refrigerant ,.-thatiaccumulates in said chamber,with the on-comingi-high-pressure liquefied impellant refrigerant andre-nebulize the same, whereby said interior surfacesofsaidheat-exchanger maybe repeated and continuouslybathed-bythenebulized liquefied refrigerant, during op erationofthe-system, until gasified and drawn from said chamber, asalowpressure gas, to beagain converted to a-high'pressure gas.-

4. Anevaporator for-a circulating volatile refrigerant systemhaving acondenser means and a compressor means, said evaporator comprisingtahollow body member forming a chamber having. an outlet removed upwardlyfrom thebottom-thereof, an atomizing injector nozzle mounted in: thebottom of said chamber for connection in a circulatingsystem-toreceiveliquefied refrigerant therefrom at substantially condenserpressure-andto function as a restrictor and positioned to. direct its emittedliquefied re= frigerant upwardly to impingeupon the interior surfaces ofsaid-chamber in a finely dividedstateand pass through saidoutlet asalowpressuregas, saidnozzle having an inspirator passage therein positionedto cause any ungasi fied refrigerant accumulating on the bottom of saidchamber to be entrained with the highpressure liquefied refrigerant,beingintroduced into said chamber, so as to be renebulized' therewith,whereby said chamber is not flooded with a liquid body-of saidrefrigerant and the surfaces of said chamber are continuouslybathed-withnebulizedliquid refrigerant, while the system is-inoperation,-until gasified and drawn from'said chamber.

5. The subject matter ofclaim 4 wherein said chamber has a sump inthe'bottom thereof into which liquid refrigerant on the bottom of saidchamber flows, saidnozzle being positioned in said sump and havingtheinspirator passage thereinwithinand communicating with the-sump, thedischarge orificeof said nozzles projecting above said sump and abovethe normal level ofanyac cumulated liquefied refrigerant in saidchamber.

6. The subject-matter of claim 4 wherein said heat exchanger isa-vertica'lly disposed enclosed hollowcasing of heat conducting materialof greater height and width than cooling" system employing a volatilerefrigerant; saidevaporator comprising a closed panel member of heatmally connected tosaid walls of said chamber to deflecta'nd pass saidrefrigerant one to the other in its downward passage in said chamber,any liquefied refrigerant accumulatingin thebottom 'of said chamber maybe repeatedly inspirated by. said nozzleor nozzles with the impelling'medium upwardly in said tube and discharged therefrom untilgasified,said chamber having a gas outlet therein adapted to beconnected inthecooling system.

9.' Incombination with a reversible heat exchange system employingavolatile refrigerant, of a heat exchanger alternately actingasa-condenser and as an evaporator upon reversed" cycles of said system,said heat exchanger being. .a vertically disposed wall-enclosed chamberhaving two opposed sides converging upwardly from its bottom,- a waterspray device arranged to direct its spray onto the exterior surfaces ofI said inclined sides of said walls,

atomizing injector nozzle means located in the bottom of said chamberandiconnected in said system with the high pressure'liquefiedrefrigerant and positioned to direct the nebulized refrigerant upwardlyinto said chamber to impinge the walls thereof, saidnozzles having aninspirator passage therein adapted tobe surrounded by liquefiedrefriger'ant accumulatin'gon thebottom of said chamber to re'atomize thesame withthe oncoming pressure charge of the liquefied refrigerant, saidchamber having an outlettherein removed upwardly from said nozzles andconnectedin said system to draw gasified refrigerant therefrom as a lowpressure; gas, whereby ice may be formed on said exterior inclinedsurfacesof said heat-exchanger andmaybe released therefrom uponreversingthe cycle ofthe system allowing said ice to move downwardly off saidsurfaces.

10L The subject matter of claim 9 wherein there is a collector toreceive excess water flowing from said inclined surfaces of the heatexchanger and connected with the water supply to said spray device, andmeans for receiving and collecting the ice dropping from said heatexchanger. v

11'. A vaporizer for a circulating volatile refrigerant comprising :ashell-like heat-exchanger in the form of a walled chamber of heatconducting material and devoid of fliiid circulating tubes therein for aseparate heat-' exchange medium and having an inlet and an outlet forsaid refrigerantto pass thereinto and therefrom, respectively',atomizing injector-nozzle means located in the bottom portion of saidheat-exchanger to be surrounded by any liquified refrigerant in thebottom of said heat exchanger for aspirating said liquified refrigerantand-connected in acirculating system at the inlet of saidheatexchanger',- said nozzle means being positioned to direct itsemitted spray to impinge upon and contact the interior surfaces-withinsaid heat-exchanger, whereby said interior surfaces ofsaidheat-exchanger may be repeatedly and continuously bathed by atomizedrefrigerant emitted from said nozzle means while the system is inoperation until gasified or vaporized.

References Cited'in thefileof this patent UNITED STATES PATENTS2,117,506 Reinhardt May 17,

2, 23,921 Y Phillips- July 5, 1938 2,132,932 Boileau Oct; 11, 1938Brizzolara' May 23, 1939 Anderson et al. Oct. 6, 1942" 2,381,589 HayesAug. 7, 1945

